(() => {
  const btfFn = {
    debounce: (func, wait = 0, immediate = false) => {
      let timeout
      return (...args) => {
        const later = () => {
          timeout = null
          if (!immediate) func(...args)
        }
        const callNow = immediate && !timeout
        clearTimeout(timeout)
        timeout = setTimeout(later, wait)
        if (callNow) func(...args)
      }
    },

    throttle: function (func, wait, options = {}) {
      let timeout, context, args
      let previous = 0

      const later = () => {
        previous = options.leading === false ? 0 : new Date().getTime()
        timeout = null
        func.apply(context, args)
        if (!timeout) context = args = null
      }

      const throttled = (...params) => {
        const now = new Date().getTime()
        if (!previous && options.leading === false) previous = now
        const remaining = wait - (now - previous)
        context = this
        args = params
        if (remaining <= 0 || remaining > wait) {
          if (timeout) {
            clearTimeout(timeout)
            timeout = null
          }
          previous = now
          func.apply(context, args)
          if (!timeout) context = args = null
        } else if (!timeout && options.trailing !== false) {
          timeout = setTimeout(later, remaining)
        }
      }

      return throttled
    },

    sidebarPaddingR: () => {
      const innerWidth = window.innerWidth
      const clientWidth = document.body.clientWidth
      const paddingRight = innerWidth - clientWidth
      if (innerWidth !== clientWidth) {
        document.body.style.paddingRight = paddingRight + 'px'
      }
    },

    snackbarShow: (text, showAction = false, duration = 2000) => {
      const { position, bgLight, bgDark } = GLOBAL_CONFIG.Snackbar
      const bg = document.documentElement.getAttribute('data-theme') === 'light' ? bgLight : bgDark
      Snackbar.show({
        text,
        backgroundColor: bg,
        showAction,
        duration,
        pos: position,
        customClass: 'snackbar-css'
      })
    },

    diffDate: (d, more = false) => {
      const dateNow = new Date()
      const datePost = new Date(d)
      const dateDiff = dateNow.getTime() - datePost.getTime()
      const minute = 1000 * 60
      const hour = minute * 60
      const day = hour * 24
      const month = day * 30
      const { dateSuffix } = GLOBAL_CONFIG

      if (!more) return parseInt(dateDiff / day)

      const monthCount = dateDiff / month
      const dayCount = dateDiff / day
      const hourCount = dateDiff / hour
      const minuteCount = dateDiff / minute

      if (monthCount > 12) return datePost.toISOString().slice(0, 10)
      if (monthCount >= 1) return `${parseInt(monthCount)} ${dateSuffix.month}`
      if (dayCount >= 1) return `${parseInt(dayCount)} ${dateSuffix.day}`
      if (hourCount >= 1) return `${parseInt(hourCount)} ${dateSuffix.hour}`
      if (minuteCount >= 1) return `${parseInt(minuteCount)} ${dateSuffix.min}`
      return dateSuffix.just
    },

    loadComment: (dom, callback) => {
      if ('IntersectionObserver' in window) {
        const observerItem = new IntersectionObserver((entries) => {
          if (entries[0].isIntersecting) {
            callback()
            observerItem.disconnect()
          }
        }, { threshold: [0] })
        observerItem.observe(dom)
      } else {
        callback()
      }
    },

    scrollToDest: (pos, time = 500) => {
      const currentPos = window.pageYOffset
      const isNavFixed = document.getElementById('page-header').classList.contains('fixed')
      if (currentPos > pos || isNavFixed) pos = pos - 70

      if ('scrollBehavior' in document.documentElement.style) {
        window.scrollTo({
          top: pos,
          behavior: 'smooth'
        })
        return
      }

      let start = null
      pos = +pos
      window.requestAnimationFrame(function step (currentTime) {
        start = !start ? currentTime : start
        const progress = currentTime - start
        if (currentPos < pos) {
          window.scrollTo(0, ((pos - currentPos) * progress / time) + currentPos)
        } else {
          window.scrollTo(0, currentPos - ((currentPos - pos) * progress / time))
        }
        if (progress < time) {
          window.requestAnimationFrame(step)
        } else {
          window.scrollTo(0, pos)
        }
      })
    },

    animateIn: (ele, text) => {
      ele.style.display = 'block'
      ele.style.animation = text
    },

    animateOut: (ele, text) => {
      ele.addEventListener('animationend', function f () {
        ele.style.display = ''
        ele.style.animation = ''
        ele.removeEventListener('animationend', f)
      })
      ele.style.animation = text
    },

    wrap: (selector, eleType, options) => {
      const createEle = document.createElement(eleType)
      for (const [key, value] of Object.entries(options)) {
        createEle.setAttribute(key, value)
      }
      selector.parentNode.insertBefore(createEle, selector)
      createEle.appendChild(selector)
    },

    isHidden: ele => ele.offsetHeight === 0 && ele.offsetWidth === 0,

    getEleTop: ele => {
      let actualTop = ele.offsetTop
      let current = ele.offsetParent

      while (current !== null) {
        actualTop += current.offsetTop
        current = current.offsetParent
      }

      return actualTop
    },

    loadLightbox: ele => {
      const service = GLOBAL_CONFIG.lightbox

      if (service === 'mediumZoom') {
        mediumZoom(ele, { background: 'var(--zoom-bg)' })
      }

      if (service === 'fancybox') {
        Array.from(ele).forEach(i => {
          if (i.parentNode.tagName !== 'A') {
            const dataSrc = i.dataset.lazySrc || i.src
            const dataCaption = i.title || i.alt || ''
            btf.wrap(i, 'a', { href: dataSrc, 'data-fancybox': 'gallery', 'data-caption': dataCaption, 'data-thumb': dataSrc })
          }
        })

        if (!window.fancyboxRun) {
          Fancybox.bind('[data-fancybox]', {
            Hash: false,
            Thumbs: {
              showOnStart: false
            },
            Images: {
              Panzoom: {
                maxScale: 4
              }
            },
            Carousel: {
              transition: 'slide'
            },
            Toolbar: {
              display: {
                left: ['infobar'],
                middle: [
                  'zoomIn',
                  'zoomOut',
                  'toggle1to1',
                  'rotateCCW',
                  'rotateCW',
                  'flipX',
                  'flipY'
                ],
                right: ['slideshow', 'thumbs', 'close']
              }
            }
          })
          window.fancyboxRun = true
        }
      }
    },

    setLoading: {
      add: ele => {
        const html = `
        <div class="loading-container">
          <div class="loading-item">
            <div></div><div></div><div></div><div></div><div></div>
          </div>
        </div>
      `
        ele.insertAdjacentHTML('afterend', html)
      },
      remove: ele => {
        ele.nextElementSibling.remove()
      }
    },

    updateAnchor: (anchor) => {
      if (anchor !== window.location.hash) {
        if (!anchor) anchor = location.pathname
        const title = GLOBAL_CONFIG_SITE.title
        window.history.replaceState({
          url: location.href,
          title
        }, title, anchor)
      }
    },

    getScrollPercent: (currentTop, ele) => {
      const docHeight = ele.clientHeight
      const winHeight = document.documentElement.clientHeight
      const headerHeight = ele.offsetTop
      const contentMath = (docHeight > winHeight) ? (docHeight - winHeight) : (document.documentElement.scrollHeight - winHeight)
      const scrollPercent = (currentTop - headerHeight) / (contentMath)
      const scrollPercentRounded = Math.round(scrollPercent * 100)
      const percentage = (scrollPercentRounded > 100) ? 100 : (scrollPercentRounded <= 0) ? 0 : scrollPercentRounded
      return percentage
    },

    addEventListenerPjax: (ele, event, fn, option = false) => {
      ele.addEventListener(event, fn, option)
      btf.addGlobalFn('pjax', () => {
        ele.removeEventListener(event, fn, option)
      })
    },

    removeGlobalFnEvent: (key, parent = window) => {
      const { globalFn = {} } = parent
      const keyObj = globalFn[key] || {}
      const keyArr = Object.keys(keyObj)
      if (!keyArr.length) return
      keyArr.forEach(i => {
        keyObj[i]()
      })
      delete parent.globalFn[key]
    }
  }

  window.btf = { ...window.btf, ...btfFn }
})()
